title: Increased local recurrence and reduced survival from colorectal cancer following anastomotic leak: systematic review and meta-analysis.
abstract: OBJECTIVE
  To examine the long-term oncological impact of anastomotic leakage (AL) after restorative surgery for colorectal cancer using meta-analytical methods. Outcomes evaluated were local recurrence, distant recurrence, and survival.
  
  
  BACKGROUND
  Recurrence after potentially curative surgery for colorectal cancer remains a significant clinical problem and has a poor prognosis. AL may be a risk factor for disease recurrence, however available studies have been conflicting. A meta-analysis was conducted to investigate the impact of AL on disease recurrence and long-term survival.
  
  
  METHODS
  Studies published between 1965 and 2009 evaluating the long-term oncological impact of AL were identified by an electronic literature search. Outcomes evaluated included local recurrence, distant recurrence, and cancer specific survival. Meta-analysis was performed using the DerSimonian-Laird random-effects model to compute odds ratio and 95% confidence intervals. Study heterogeneity was evaluated using Q statistics and I and publication bias assessed with funnel plots and Egger's test.
  
  
  RESULTS
  Twenty-one studies comprising 13 prospective nonrandomized studies, 1 prospective randomized, and 7 retrospective studies met the inclusion criteria, yielding a total of 21,902 patients. For rectal anastomoses, the odd ratios (OR) of developing a local recurrence when there was AL was 2.05 (95% CI = 1.51-2.8; P = 0.0001). For studies describing both colon and rectal anastomoses, the OR of local recurrence when there was an AL was 2.9 (95% CI = 1.78-4.71; P < 0.001). The OR of developing a distant recurrence after AL was 1.38 (95% CI = 0.96-1.99; P = 0.083). Long term cancer specific mortality was significantly higher after AL with an OR of 1.75 (95% CI = 1.47-2.1; P = 0.0001).
  
  
  CONCLUSIONS
  AL has a negative prognostic impact on local recurrence after restorative resection of rectal cancer. A significant association between colorectal AL and reduced long-term cancer specific survival was also noted. No association between AL and distant recurrence was found.
authors.affiliation: Somers Cancer Research Building, University of Southampton Cancer Sciences Division, Southampton University Hospital NHS Trust, Tremona road, Southampton, United Kingdom. ahm@soton.ac.uk
authors.forename: Alexander
authors.initials: A
authors.lastname: Mirnezami
authors.forename: Reza
authors.initials: R
authors.lastname: Mirnezami
authors.forename: Kandiah
authors.initials: K
authors.lastname: Chandrakumaran
authors.forename: Kishore
authors.initials: K
authors.lastname: Sasapu
authors.forename: Peter
authors.initials: P
authors.lastname: Sagar
authors.forename: Paul
authors.initials: P
authors.lastname: Finan
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000714:Anastomosis, Surgical / Q000009:adverse effects / Q000379:methods; D057868:Anastomotic Leak / Q000209:etiology / Q000401:mortality*; D003082:Colectomy / Q000009:adverse effects / Q000379:methods; D015179:Colorectal Neoplasms / Q000453:epidemiology* / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology* / Q000473:pathology; D018570:Risk Assessment; D012737:Sex Factors; D016019:Survival Analysis; D013997:Time Factors